ANDROID: mm: page_pinner: change output format for alloc_contig_failed

Currently, output format is a little hard to parse how long the
page has been pinned since user need to figure out the timeline
from migration failure detection to put event. Sometimes, the log
buffer would be overflowed so we lost the migration failure event
timeline, even. This patch stores the page pinning time in kernel
side and keep the information whenever page was released. Thus,
user could understand the output easier and never lose the information.

Bug: 218731671
Signed-off-by: Minchan Kim <minchan@google.com>
Change-Id: I396f0c12438e0ff8a3497253b750a7e5bb342f57